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Re: Sickle-Clawed birds
David Marjanovic wrote-
> There is a reconstruction of Patagopteryx in The Dinosauricon showing it
> a basal alvarezsaur. Judging by how little is known of the skeleton (e. g.
> the tail is completely unknown, the arms "end" just below the elbows), and
> by the fact that it was described before Mononykus, this is possible.
> However, T. Mike Keesey still puts it into Euornithes and allies it with
> Gargantuavis and Kuszholia as Patagopterygiformes (interesting and not
> implausible, but I don't have an idea why).
Patagopteryx is a separate OTU in my analysis, which places it as the sister
group to ornithurines, not in the Alvarezsauridae (which is represented by
Alvarezsaurus, Patafonykus and Mononykinae in my analysis). I'd list
features to support it's inclusion in the Pygostylia, but my character lists
are all in my other, nonfunctional computer for now. As for Gargantuavis
and Kuszholia, I hear the first is a pygostylian and the second just may be
non-avian, then again it might be a bird. I'm sure to do a "Details on..."
segment on it sometime in the future.
> Sickle claws or hyperextendable toes or whatever are said to occur in
> Ornitholestes, too, so maybe that's a coelurosaurian or neotetanuran
> synapomorphy lost several times.
Unfortunately, the figure of the pes in dorsal view by Ostrom (1969) is the
best illustrated and it merely shows that Ornitholestes has an enlarged
second pedal ungual compared to other unguals (~125% of ungual III). It is
unnown whether it also had a hyperextendable sencond digit, enlarged heel on
phalanx II-2, large flexor tubercle on pedal ungual II or the narrow cross
section this ungual has in dromaeosaurs.